Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already indicate readOnlyHint=true and openWorldHint=true, and the description adds deeper behavioral context: it reads the connected channel directly, needs no input, derives ideas from winners and comments, and must not prompt the user. It also clarifies that the tool generates from scratch, which is valuable beyond the annotation hints.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose and includes useful trigger phrases and exclusions. It is somewhat repetitive near the end ('Needs no input' and 'Never ask...call it immediately' restate the same point), but each section still earns its place by addressing usage, alternatives, and parameter handling.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers how to invoke the tool, when to use it, what it reads, and what to avoid. Since there is no output schema, a brief note about the shape or format of the returned ideas would improve completeness, but the current description is sufficient for an agent to call the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Although schema coverage is 100%, the description adds crucial operational guidance for the optional 'subjects' parameter: only pass what the user explicitly said, never guess, and Klyf derives these from the search report otherwise. This tells the agent exactly when and how to populate the parameter, beyond the schema's basic definition.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Generate') and resource ('specific video ideas for the signed-in user's own YouTube channel'), and clearly differentiates from evaluate_idea by noting this tool generates from scratch rather than judging an existing idea. This makes the tool's purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit trigger conditions ('asks what to make, film, or post next...'), explicitly names the alternative for a different scenario ('use evaluate_idea instead'), and instructs the agent to call it immediately without asking the user questions. This fully routes the agent to the correct tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.